Generally, the conventional sailboat keel is rigid and by providing a low center of gravity serves to oppose the heeling moment applied to the sail area only by the action of the boat in heeling over. In my prior patent, U.S. Pat. No. 4,044,703, granted Aug. 30, 1977, I disclosed a keel design which included a pair of complementary keel sections which could be angularly positioned either independently or as a locked together unit for exerting a moment opposing the heeling moment applied to the sail area and allowing the boat to remain upright. By the boat remaining upright, the horizontal component of wind force upon the sail area is maximized. The angle between the keel sections determines the draft and roll moment of inertia of the boat, while the orientation of the bisector of the angle between the keel sections determines generally the moment opposing the heeling tendency. That design utilized flexible lines to support the keel sections at desired orientations such that any upward forces applied to the keel sections would not be transmitted to the hull of the boat since the keel sections alone would tend to rotate upward. That feature is desireable in terms of eliminating shock to the hull as from a grounding.
However, according to my present invention, by utilizing means to variably position and hold the keel sections substantially rigidly positioned so that the keel can transmit upward forces to the hull, various useful and novel features are possible.
As one feature, the axis of the keel may be adjusted in elevation so that hydrodynamic lift and yaw forces are applied to the inclined keel means by means of reaction of the water upon the moving sailboat so as to provide desireable lift of the boat and yaw toward the wind, referred to as "lift to windward".
In a second feature, the keel sections may be configured to accept removable wheels to enable the boat to be self-trailered.